For what value of c are the three points (-3,1), (5,5), and (6,c) on the same line?

Guest Feb 16, 2020

#1

#1**0 **

The slope between the points (-3,1) and (5,5) is 8/4 = 2. Then by point-slope form, the equation of the line is y - 1 = 2(x + 3), or y = 2x + 7. So when x = 6, c = 2*6 + 7 = 19.

Guest Feb 16, 2020

#8**+2 **

**For what value of c are the three points (-3,1), (5,5), and (6,c) on the same line?**

\(\begin{array}{|rcll|} \hline \dfrac{c-5}{6-5} &=& \dfrac{5-1}{5-(-3)} \\\\ c-5 &=& \dfrac{4}{8} \\\\ c-5 &=& \dfrac{1}{2} \\\\ c &=& 5+ \dfrac{1}{2} \\\\ \mathbf{c} &=& \mathbf{5.5} \\ \hline \end{array}\)

heureka Feb 17, 2020